Inheritance: incomplete autosomal dominant/semidominant → Horses with one or two copies of the variant (n/P1 or P1/P1) are affected. Incomplete or semidominant means that animals with one copy (n/P1) may show milder symptoms and a later age of onset than animals with two copies (P1/P1).

Possible genotypes:

Genotype:

The horse is:

Effects:

n/n

normal.

The horse does not have any copy of P1 and therefore cannot pass it on to any offspring.

n/P1

affected (heterozygous).

The horse has one copy of P1 and will pass it on to approximately 50% of its offspring. These 50% are at risk of developing PSSM1.

P1/P1

affected (homozygous).

The horse has two copies of P1 and will pass it on to 100% of its offspring. All offspring will be at risk of developing PSSM1.

Recommendations:

Affected horses (n/P1 or P1/P1) should only be bred after careful consideration and with the advice of a genetic expert and veterinarian. Please contact us for consultation and support.

Test information: This test identifies a mutation in the GYS1 gene.This test is performed by partner laboratory.